Melbourne - Australian teen Bernard Tomic stole the show on day one of the Australian Open Monday with an epic five-set upset of Spain's Fernando Verdasco, as Juan Martin del Potro safely launched his campaign.
Tomic, his country's top-ranked men's player at 38, dug deep as he came from two sets down to oust the experienced 22nd seed in four hour-plus thriller on a sweltering Rod Laver Arena.
The 19-year-old produced the finest performance of his fledgling professional career to reel in Verdasco in only his third five-setter.
The gruelling victory played out in 34 Celsius (93 Fahrenheit) temperatures again showcased Tomic's enormous potential after he became the youngest man in 25 years to reach the quarter-finals of last year's Wimbledon.
"Anything's possible if you keep trying," Tomic said. "Same thing happened at Wimbledon when I was in the second round. I was losing two sets to love down and made the quarters.
"Anything is possible. Can't always give up. You can learn about yourself, and, yeah, how in the future you can play."
Verdasco looked on course to wipe Tomic in straight sets, powering through the opening two sets before the Australian broke the Spaniard in the ninth game of the third set to sight a glimmer of hope.
And Tomic grew stronger in the heat, while Verdasco showed more signs of weariness and he took the match into a fifth set.
"Had I not done that fitness (training) the last two, three months, there's no way mentally you can be out there in that heat and turn around in a match like that and win," Tomic said.
"I think it was all fitness, the way I've been preparing the last few months. It's all paid off."
In a gripping final set Verdasco needed his big serving to fight off Tomic before he was broken in the 11th game, allowing the teenager to serve out for a courageous win.
In the second round Tomic will play American Sam Querrey, who beat French wild card Kenny de Schepper in straight sets.
Del Potro needed four sets and three hours to reach the second round in overcoming French world number 91 Adrian Mannarino on Hisense Arena.
The former US Open champion dropped the opening set before going through 2-6, 6-1, 7-5, 6-4.
Del Potro, who has never lost an opening round match in seven visits to Melbourne, picked up his game to finish too powerfully for the fleet-footed Frenchman.
"He started much better than me in the first set, and then it was tough to fight behind the score," del Potro said.
"But I did my things, my game, and I took all the opportunities to beat him."
The Argentine giant will now face Slovenia's Blaz Kavcic in the second round after Kavcic's straight-sets win over Britain's James Ward.
Elsewhere, Czech seventh seed Tomas Berdych accounted for Spaniard Albert Ramos in four sets, Swiss Stanislas Wawrinka eased past Frenchman Benoit Paire in straight sets and American eighth seed Mardy Fish downed Luxembourg's Gilles Muller for the loss of 10 games.
Spanish 10th seed Nicolas Almagro knocked out Poland's Lukasz Kubot, 1-6, 7-5, 6-3, 7-5 and Germany's Tommy Haas ousted American qualifier Denis Kudla in four sets.